This was discussed today about how it would affect snapd-glib and graphical clients (e.g. GNOME Software).
The snapd-glib API reflects the information as provided by snapd, so changes to track names and behaviours will not break anything there.
GNOME Software provide the user with the available channels to use, and the user then decides which one to select. I would expect other graphical clients to do the same thing. So the user might be presented with slightly different choices, but as long as they understand the meaning of channels they should still be able to effectively use them.
snapcraft.io seems to use full names for channels rather than abbreviations. GNOME Software currently uses the abbreviations but I think it should switch to full names to avoid any confusion here. There’s no need for abbreviations here as they’re selected with a mouse pointer, not typed in via keyboard.